Advanced chipkill memory
RAM modules with an extra ASIC for RAID5 functionality. So even if a complete
module fails it can be replaced without data loss (IBM
development)

Bank
A slot or group of slots, usually on a system board, that are populated by memory
modules of the same capacity, type and speed.

Bit
Binary Digit - the smallest piece of data (a 1 or a 0) that a computer recognizes.

Byte
A series of 8 bits.

Clock Rate
The number of pulses emitted from a computer's clock in one second. This determines
the rate at which logical or arithmetic gating is performed in a synchronous computer.

DDR SDRAM (SDRAM II)
Double Data Rate SDRAM. Same as SDRAM, but data is transferred at twice the rate.

DIMM
Dual Inline Memory Module. A module with signal and power pins on both sides of
the memory module.

DRAM
Dynamic Random Access Memory is most commonly used type of computer memory. It
usually uses one transistor and a
capacitor to represent a bit. The capacitors must be energized hundreds of times
per second in order to maintain the charges. Unlike firmware chips
(ROMs, PROMs, etc.) both major varieties of RAM (dynamic and static) lose their
content when the power is turned off.

ECC
Error Checking and Correction. A method of detecting and correcting system memory
errors by adding additional bits and using a special algorithm.

Lead
The leg or contact point of the component that is placed within a socket for connection.

Megabit (Mb) = 1,000 Kilobits. 1Mb = 1,048,576 bits.

Megabyte (MB)= 1,000 Kilobytes. 1MB = 1,048,576 bytes.

Nanosecond (ns)
One billionth of a second.

Printed Circuit Board (PCB)
A flat board that holds chips and other electronic components. The board is made
of reinforced fiberglass or plastic and interconnects components via copper pathways.
The main printed circuit board in a system is called a system board or motherboard,
while
smaller ones that plug into the slots in the main board are called boards or cards.

Random Access Memory (RAM)
A group of memory chips, typically of the dynamic RAM (DRAM) type, which functions
as the computer's primary workspace.

RDRAM (Direct Rambus)
RDRAM is a unique design developed by a company called Rambus, Inc. RDRAM is extremely
fast and uses a narrow, high-bandwidth channel to transmit data at
speeds about ten times faster than standard DRAM. Two other flavors of RDRAM are
also soon to arrive: Concurrent and Direct RDRAM. Concurrent is based on the fundamental
design of the standard RDRAM, yet is enhanced to increase speed and performance.
Direct is also based on RDRAM, yet through additional enhancements will be even
faster than concurrent RDRAM.

Refresh
To continuously charge a device that cannot hold its content. CRTs must be refreshed,
because the phosphors hold their glow for only a few milliseconds. Dynamic RAM
chips require refreshing to maintain their charged bit patterns.

SDRAM
Synchronous DRAM uses a clock to synchronize signal input and output on a memory
chip. The clock is coordinated with the CPU clock so the timing of the memory
chips and the timing of the CPU are in sync. Synchronous DRAM saves
time in executing commands and transmitting data, thereby increasing the overall
performance of the computer. In pure speed tests, SDRAM is about 50 percent faster
than EDO memory, with actual performance gains of around 25 percent.

SGRAM
A type of dynamic RAM chip that is similar to the SDRAM technology, but includes
enhanced graphics features for use with display adapters. Its Block Write and
Mask Write functions allow the frame buffer to be cleared faster and selected
pixels to be modified faster.

Single Inline Memory Module (SIMM)
A module with signal and power pins on one side of the memory module.

SLDRAM
Formerly known as "SyncLink DRAM," it uses a revolutionary bus interface similar
to RDRAM but is being standardized in JEDEC as an open standard. SLDRAM is an
enhanced line extension of SDRAM architecture that extends the current four-bank
design to 16 banks.

Small Outline Dual Inline Memory Module (SODIMM)
A DIMM module with a thinner profile due to the use of TSOP chip packages. SO
DIMMs are commonly used in laptop computers.

Small Outline J-lead (SOJ)
A small-dimension, plastic, rectangular surface mount chip packages with j-shaped
pins on its two long sides.

Static Random Access Memory (SRAM)
A memory chip that requires power to hold itsí content. Static RAM chips have
access times in the 10 to 30-nanosecond range. Dynamic RAMs are usually above
30ns, and Bipolar and ECL memories are under 10ns.

Thin Small Outline Package (TSOP)
A very-thin, plastic, rectangular surface mount chip package with gull-wing pins
on its two short sides. TSOPs are about a third as thick as SOJ chips.

Video Random Access Memory (VRAM)
Is a type of memory used in a display adapter. It is designed with dual ports
so that it can simultaneously refresh the screen while text and images are drawn
in memory. It is faster than the common dynamic RAM (DRAM) used as main memory
in the computer.